CN113475117A

CN113475117A - Cell reselection method and unmanned aerial vehicle terminal

Info

Publication number: CN113475117A
Application number: CN201980092881.5A
Authority: CN
Inventors: 尤心; 卢前溪
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-07-30
Filing date: 2019-07-30
Publication date: 2021-10-01
Also published as: WO2021016894A1

Abstract

A method for reselecting a cell and a unmanned aerial vehicle terminal are provided, and the method comprises the following steps: obtaining altitude information for at least one candidate cell; determining a target cell from the at least one candidate cell according to the altitude information and the flight mode of the unmanned aerial vehicle terminal; and performing cell reselection based on the target cell. Based on the technical scheme, the height information aiming at least one candidate cell is introduced to the cell reselection process of the unmanned aerial vehicle terminal, so that the unmanned aerial vehicle terminal can preferentially select the cell with the largest coverage height interval when the cell is reselected according to different flight modes, frequent cell reselection caused by the flight process is avoided, the residence time in the reselected cell is prolonged, time guarantee is provided for connection establishment, the probability of establishment failure caused by cell reselection in the connection establishment process is reduced, and the success rate of data transmission and the user experience are further improved.

Description

Cell reselection method and unmanned aerial vehicle terminal

Technical Field

The embodiment of the application relates to the field of communication, and in particular relates to a cell reselection method and an unmanned aerial vehicle terminal.

Background

Currently, in order to meet the pursuit of speed, delay, high-speed mobility and energy efficiency by people and the demand for diversification and complication of services in future life, the 3GPP international standards organization has started to develop 5G. The main application scenarios of 5G are: enhanced mobile ultra-wideband (eMBB), low-latency high-reliability communication (URLLC), and large-scale machine type communication (mMTC).

Furthermore, Unmanned Aerial Vehicles (UAVs), simply referred to as drone terminals, have a global market that has grown substantially over the past decade and have now become an important tool for commercial, government and consumer applications. The unmanned aerial vehicle can support solutions in various fields, and can be widely applied to the fields of buildings, petroleum, natural gas, energy, public utilities, agriculture and the like. Currently, the unmanned aerial vehicle technology is developing at a high speed towards the direction of military and civil integration, and the unmanned aerial vehicle industry is the most active emerging market of international aerospace, and becomes a bright spot of economic growth of each country.

However, currently, in 5G, the cell deployment mainly serves terminal devices on the ground, and the network coverage is mainly a ground two-dimensional space. After introducing the unmanned aerial vehicle terminal, because unmanned aerial vehicle can lift off, unmanned aerial vehicle communication needs also to carry out network deployment on certain height. Based on this, the network deployment approach is to add new network coverage for different altitudes.

Frequent cell reselection procedures may result if the drone terminal only considers existing RSRP/RSRQ and other measurements during cell reselection. In addition, if cell reselection occurs when the unmanned aerial vehicle terminal is establishing a data transmission connection, the connection establishment may be terminated or failed, so as to increase data transmission delay and even cause data transmission failure, thereby reducing the success rate of data transmission and user experience.

Disclosure of Invention

The cell reselection method and the unmanned aerial vehicle terminal are provided, and the success rate of data transmission and the user experience can be improved.

In a first aspect, a method for reselecting a cell is provided, including:

obtaining altitude information for at least one candidate cell;

determining a target cell from the at least one candidate cell according to the altitude information and the flight mode of the unmanned aerial vehicle terminal;

and performing cell reselection based on the target cell.

In a second aspect, a drone terminal is provided for performing the method of the first aspect or its implementations. Specifically, the drone terminal includes a functional module configured to perform the method in the first aspect or each implementation manner thereof.

In a third aspect, a drone terminal is provided that includes a processor and a memory. The memory is configured to store a computer program, and the processor is configured to call and execute the computer program stored in the memory to perform the method in the first aspect or each implementation manner thereof.

In a fourth aspect, a chip is provided for implementing the method in the first aspect or its implementation manners. Specifically, the chip includes: a processor, configured to call and run a computer program from a memory, so that a device in which the chip is installed performs the method according to the first aspect or each implementation manner thereof.

In a fifth aspect, a computer-readable storage medium is provided for storing a computer program, the computer program causing a computer to execute the method of the first aspect or its implementation modes.

A sixth aspect provides a computer program product comprising computer program instructions for causing a computer to perform the method of the first aspect or its implementations.

In a seventh aspect, a computer program is provided, which, when run on a computer, causes the computer to perform the method of the first aspect or its implementations.

Based on the technical scheme, the height information aiming at least one candidate cell is introduced to the cell reselection process of the unmanned aerial vehicle terminal, so that the unmanned aerial vehicle terminal can preferentially select the cell with the largest coverage height interval when the cell is reselected according to different flight modes, frequent cell reselection caused by the flight process is avoided, the residence time in the reselected cell is prolonged, time guarantee is provided for connection establishment, the probability of establishment failure caused by cell reselection in the connection establishment process is reduced, and the success rate of data transmission and the user experience are further improved.

Drawings

Fig. 1 is an example of an application scenario of the present application.

Fig. 2 is a schematic flow chart of a method for reselecting a cell according to an embodiment of the present application.

Fig. 3 to 5 are schematic block diagrams of a coverage area of a first candidate cell, a coverage area of a second candidate cell, and a position relationship of an unmanned aerial vehicle terminal according to an embodiment of the present application.

Fig. 6 is a schematic block diagram of an unmanned aerial vehicle terminal according to an embodiment of the present application.

Fig. 7 is a schematic block diagram of a communication device of an embodiment of the present application.

Fig. 8 is a schematic block diagram of a chip of an embodiment of the present application.

Detailed Description

Technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 is a schematic diagram of an application scenario of an embodiment of the present application.

As shown in fig. 1, communication system 100 may include a terminal device 110 and a network device 120. Network device 120 may communicate with terminal device 110 over the air. Multi-service transport is supported between terminal device 110 and network device 120.

It should be understood that the embodiment of the present application is only illustrated as the communication system 100, but the embodiment of the present application is not limited thereto. That is to say, the technical solution of the embodiment of the present application can be applied to various communication systems, for example: a Long Term Evolution (LTE) System, a Time Division Duplex (TDD) System, a Universal Mobile Telecommunications System (UMTS), a 5G communication System (also referred to as a New Radio (NR) communication System), a future communication System, or the like.

In communication system 100 shown in fig. 1, network device 120 may be an access network device that communicates with terminal device 110. An access network device may provide communication coverage for a particular geographic area and may communicate with terminal devices 110 (e.g., UEs) located within the coverage area.

Alternatively, the Network device 120 may be an evolved Node B (eNB or eNodeB) in a Long Term Evolution (Long Term Evolution, LTE) system, or a Next Generation Radio Access Network (NG RAN) device, or a base station (gNB) in an NR system, or a Radio controller in a Cloud Radio Access Network (CRAN), or the Network device 120 may be a relay station, an Access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, or a Network device in a Public Land Mobile Network (PLMN) for future Evolution, or the like.

Optionally, the terminal device 110 may be any drone terminal device, including but not limited to: terminal devices that employ wired or wireless connections with network device 120 or other terminal devices. Terminal Equipment may refer to an access terminal, User Equipment (UE), subscriber unit, subscriber station, mobile station, remote terminal, mobile device, User terminal, wireless communication device, User agent, or User Equipment. An access terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having Wireless communication capabilities, a computing device or other processing device connected to a Wireless modem, a vehicle mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolution network, etc.

Optionally, Device-to-Device (D2D) communication may be performed between terminal devices 110.

The wireless communication system 100 may further include a Core network device 130 in communication with the base station, where the Core network device 130 may be a 5G Core (5G Core, 5GC) device, such as an Access and Mobility Management Function (AMF), an Authentication Server Function (AUSF), a User Plane Function (UPF), and a Session Management Function (SMF). Alternatively, the Core network device 130 may also be an Evolved Packet Core (EPC) device of the LTE network, for example, a Session Management Function + Core Packet Gateway (SMF + PGW-C) device of the Core network. It is understood that SMF + PGW-C may perform the functions that SMF and PGW-C can perform simultaneously. In the network evolution process, the core network device may also be called by other names, or a new network entity is formed by dividing the functions of the core network, which is not limited in this embodiment of the present application.

In a specific example, communication between functional units in communication system 100 may be achieved by establishing a connection through a next generation Network (NG) interface.

For example, the terminal device establishes an air interface connection with the access network device through the NR interface, and is used to transmit user plane data and control plane signaling; the terminal equipment can establish control plane signaling connection with the AMF through an NG interface 1 (N1 for short); the access network equipment, such as a next generation radio access base station (gNB), can establish a user plane data connection with the UPF through an NG interface 3 (N3 for short); the access network equipment can establish a control plane signaling connection with the AMF through an NG interface 2 (N2 for short); the UPF can establish a control plane signaling connection with the SMF through an NG interface 4 (N4 for short); the UPF may interact with the data network via NG interface 6 (abbreviated N6); the AMF can establish a control plane signaling connection with the SMF through an NG interface 11 (N11 for short); the SMF may establish a control plane signaling connection with the PCF via NG interface 7 (abbreviated N7). It should be noted that the part shown in fig. 2 is only an exemplary architecture diagram, and besides the functional units shown in fig. 1, the network architecture may also include other functional units or functional entities, such as: the core network device may further include other functional units such as a unified data management function (UDM), which is not specifically limited in this embodiment of the present application.

Fig. 1 exemplarily shows one base station, one core network device, and two terminal devices, and optionally, the wireless communication system 100 may include a plurality of base station devices and may include other numbers of terminal devices within the coverage area of each base station, which is not limited in this embodiment of the present application.

It should be understood that, in the embodiments of the present application, devices having a communication function in a network/system may be referred to as communication devices. Taking the communication system 100 shown in fig. 1 as an example, the communication device may include a network device 120 and a terminal device 110 having a communication function, and the network device 120 and the terminal device 110 may be the devices described above and are not described herein again; the communication device may also include other devices in the communication system 100, such as other network entities, for example, a network controller, a mobility management entity, and the like, which is not limited in this embodiment.

It should be understood that the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

Taking the communication system as 5G as an example, in a 5G network environment, a new RRC state, that is, an RRC _ INACTIVE state, is defined for the purposes of reducing air interface signaling, quickly recovering wireless connection, and quickly recovering data service. This state is different from the RRC _ IDLE and RRC _ ACTIVE states.

For RRC _ IDLE, there is no RRC connection. Mobility is UE-based cell selection reselection, paging is initiated by the Core Network (CN), and the paging area is configured by the CN. The network device side does not have a UE AS context.

For RRC _ CONNECTED, there is an RRC connection, and the network device and UE have a UE AS context. The network equipment side knows that the location of the UE is at a specific cell level. Mobility is network side controlled mobility. Unicast data may be transmitted between the UE and the network device.

For RRC _ INACTIVE, mobility is UE-based cell selection reselection, there is a connection between CN-NRs, UE AS context exists on a certain network device, paging is triggered by RAN, RAN-based paging area is managed by RAN, and the network device side knows that the location of UE is based on the paging area level of RAN.

Currently, terminal equipment on the ground is mainly served by the deployment of the cell in 5G, and the network coverage is mainly a ground two-dimensional space. After introducing the unmanned aerial vehicle terminal, because unmanned aerial vehicle can lift off, unmanned aerial vehicle communication needs also to carry out network deployment on certain height. Based on this, the network deployment approach is to add new network coverage for different altitudes.

However, if the drone terminal only considers existing RSRP/RSRQ etc. measurements during cell reselection, frequent cell reselection procedures may result. In addition, if cell reselection occurs when the unmanned aerial vehicle terminal is establishing a data transmission connection, the connection establishment may be terminated or failed, so as to increase data transmission delay and even cause data transmission failure, thereby reducing the success rate of data transmission and user experience. For example, different movement patterns of the drone (e.g., take-off, flight, landing, etc.) present problems for cell reselection.

The application provides a method for reselecting a cell and an unmanned aerial vehicle terminal, which can improve the success rate of data transmission and user experience.

Fig. 2 shows a schematic flow diagram of a method 200 of reselecting a cell according to an embodiment of the present application, which method 200 may be performed by a terminal device. The terminal device shown in fig. 2 may be the terminal device 110 shown in fig. 1.

As shown in fig. 2, the method 200 includes:

s210, the unmanned aerial vehicle terminal acquires altitude information aiming at least one candidate cell.

S220, the unmanned aerial vehicle terminal determines a target cell in the at least one candidate cell according to the altitude information and the flight mode of the unmanned aerial vehicle terminal.

S230, the unmanned aerial vehicle terminal performs cell reselection based on the target cell.

For example, after obtaining the cell height information of the serving cell and/or the neighboring cell, the drone terminal determines, as the at least one candidate cell, at least one cell that satisfies a cell selection criterion (e.g., an S criterion) based on a channel measurement result; after the at least one candidate cell is screened out by the unmanned aerial vehicle terminal, acquiring altitude information aiming at the at least one candidate cell in the cell altitude information, determining the target cell in the at least one candidate cell based on the flight mode of the unmanned aerial vehicle terminal and the altitude information, and residing in the target cell to complete the cell reselection process.

By introducing the altitude information aiming at least one candidate cell into the cell reselection process of the unmanned aerial vehicle terminal, the unmanned aerial vehicle terminal can preferentially select the cell with the largest coverage altitude interval when the cell is reselected according to different flight modes, frequent cell reselection caused by the flight process is avoided, the residence time in the reselected cell is increased, time guarantee is provided for connection establishment, the probability of establishment failure caused by cell reselection in the connection establishment process is reduced, and the success rate of data transmission and the user experience are further improved.

In some embodiments of the present application, the at least one candidate cell comprises a serving cell of the drone terminal and/or at least one neighbor cell of the serving cell.

In some embodiments of the present application, the height information comprises at least one of the following information:

an upper bound height for coverage of each of the at least one candidate cell;

a lower bound height covered by each of the at least one candidate cell; and

an altitude at which the network device to which the at least one candidate cell belongs is located.

For example, the altitude information may include a coverage of each of the at least one candidate cell in an altitude direction, or the altitude information may include an altitude interval covered by each of the at least one candidate cell.

It should be understood that the height of the network device may be the height of a component of the network device, and the height of the network device may be the height of the network device in the vertical direction, such as an altitude, a location height that does not include latitude and longitude information, or a location height that includes latitude and longitude information.

In some embodiments of the present application, each of the at least one candidate cell meets cell selection criteria to ensure that the signal quality after the drone terminal camped on the target cell is good enough.

For example, the at least one candidate cell may include at least one low priority inter-frequency cell and/or at least one high priority inter-frequency cell that satisfy a cell selection criterion.

Alternatively, the at least one candidate cell may include at least one pilot cell (also referred to as a low priority pilot cell) having a frequency point priority lower than that of the serving cell; and/or at least one pilot frequency cell (also called high priority pilot frequency cell) with a higher frequency point priority than the frequency point priority of the serving cell.

For another example, the at least one candidate cell may include at least one intra-frequency cell and/or at least one co-priority inter-frequency cell.

Or, the at least one candidate cell may include at least one pilot cell (also referred to as a same-priority pilot cell) having a frequency point priority equal to a frequency point priority of the serving cell; and/or an intra-frequency cell (also referred to as an intra-frequency cell) having a frequency point equal to a frequency point of a serving cell.

To facilitate understanding of the scheme of the present application, a brief description of cell selection criteria follows.

For example, the cell selection criterion may be an S-criterion.

The S criterion means: if Srxlev is greater than 0, the cell is resident. The Srxlev calculation formula is as follows:

Srxlev＝Qrxlevmeas-Qrxlevmin-Pcompensation；

wherein, Qrxlevmeas is the measured current serving cell received power, i.e. the measured value (dBm) of cell P-CCPCH RSCP; the Qrxlevmin is the minimum receiving power of the serving cell, that is, the minimum receiving level value (dBm) required by the cell, and may be obtained by directly obtaining from the system broadcast message or by converting based on the information obtained from the system broadcast message; pcompensation is a compensation value.

Pcompennsation can be calculated by the following formula:

Pcompensation＝max(UE_TXP-WR_MAX_RACH-P_MAX，0)。

wherein, UE _ TXPWR _ MAX _ RACH is a maximum transmission power value (dBm) allowed on the RACH channel when the terminal device accesses the cell, and is sent by a system broadcast message and is generally set to 0; p _ MAX is the maximum transmit power (dBm) of the terminal.

It is to be understood that the neighboring cells of the drone terminal may include one or more cells, the serving cell of the drone terminal may also include one or more cells, and the at least one candidate cell may be a cell that the drone terminal filters among the neighboring cells and/or serving cells of the drone terminal that satisfies the cell selection criterion (e.g., S-criterion).

In other words, the drone terminal selects a target cell satisfying a cell reselection criterion among at least one candidate cell satisfying the cell selection criterion (e.g., S criterion), and then camps on the target cell to complete a cell reselection process.

For further understanding of the scheme of the present application, a brief description of a cell reselection scheme follows.

It should be noted that, a target cell may be selected from at least one candidate cell satisfying the cell selection criterion, and then a cell reselection procedure may be performed based on the target cell. The cell reselection process is executed by the unmanned aerial vehicle terminal in the IDLE state, and may also be executed by the unmanned aerial vehicle terminal in the inactive state, which is not specifically limited in this application.

As an example, the reselection criterion may be an R criterion.

The following criteria need to be followed when the pilot frequency cells with the same frequency and the same priority are reselected:

Rs＝Q _meas,s+Q _hyst–Qoffset _temp。

Rn＝Q _meas,n-Qoffset–Qoffset _temp。

wherein Q is_meas,sIs the RSRP measurement, Q, of the serving cell_meas,nIs RSRP measurement of a neighbor cell, Qoffset is an offset value, Qoffset_tempIs a temporary offset value, Q_hystIs a hysteresis value.

If the network does not configure the strongest signal threshold (rangeToBestCell), the terminal equipment ranks the Rs and Rn values of the serving cell and the neighbor cells, and selects the cell with the highest Rs/Rn rank among the serving cell and the multiple neighbor cells to reselect the cell.

If the network is configured with a rangeToBestCell, the UE selects the cell with the highest number of good beams (beams) among the highest ranked cells defined by the parameter rangeToBestCell for reselection, where the good beams are defined by the absThreshSS-BlocksConsolidation threshold. If there are many such cells, the terminal device reselects to the highest ranked cell.

The following criteria are followed when the high priority inter-frequency cell is reselected:

if the system message broadcasts threshServingLowQ, the RSRQ of a neighboring cell on the high priority frequency point is measuredThe magnitude satisfies more than Thresh_X,HighQWhen the threshold value is reached, the terminal equipment triggers the reselection process to the cell; otherwise, the RSRP measured value of one adjacent cell on the high-priority frequency point meets the condition that the RSRP measured value is larger than Thresh_X,HighPWhen the threshold value is reached, the UE triggers the reselection process to the cell.

The following criteria are followed in the reselection of the low priority inter-frequency cell:

if the system message broadcasts threshServingLowQ, when the RSRQ of the service cell is less than Thresh_Serving,LowQAnd the RSRQ measured value of one adjacent cell on the low-priority frequency point is more than Thresh_X,HighQWhen the threshold value is reached, the terminal equipment triggers the reselection process to the cell; otherwise, when the RSRP of the service cell is less than Thresh_Serving,LowPAnd the RSRP measured value of one adjacent cell on the low-priority frequency point is more than Thresh_X，HighPWhen the threshold value is reached, the UE triggers the reselection process to the cell.

In some embodiments of the present application, the flight mode of the drone terminal may include at least one of:

takeoff mode, horizontal flight mode, and landing mode.

The takeoff mode may refer to that the height of the unmanned aerial vehicle terminal is in a continuously rising state within a certain time period, and the duration of the certain time period may be less than or equal to a certain threshold. Similarly, the horizontal flight mode may refer to that the range of fluctuation of the height of the drone terminal up and down is smaller than a certain preset range within a certain time period, and the landing mode may refer to that the height of the drone terminal is in a continuous descent state within a certain time period.

The following describes an implementation of S220 in detail.

In S220, the drone terminal may determine, in the at least one candidate cell, a target cell according to the altitude information for the at least one candidate cell and a flight mode of the drone terminal.

In some embodiments of the present application, the drone terminal may determine, in the at least one candidate cell, a target cell directly based on the altitude information of the at least one candidate cell and the flight mode of the drone terminal, avoiding using additional information to be compatible as much as possible with a cell reselection process in a two-dimensional space.

Specifically, the target cell may be determined in the following manner:

1) if the unmanned aerial vehicle terminal is in a take-off mode, the unmanned aerial vehicle terminal can determine the cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or if the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can determine a cell covered by a network device with the largest height in at least one network device to which the at least one candidate cell belongs as the target cell.

Fig. 3 is a schematic block diagram of a coverage area of a first candidate cell, a coverage area of a second candidate cell, and a position relationship of an unmanned aerial vehicle terminal according to an embodiment of the present application.

Referring to fig. 3, the at least one candidate cell includes a first cell covered by the first network device 310 and a second cell covered by the second network device 320, where if the lower limit height of the coverage area of the second cell is an x-axis, and the vertical direction perpendicular to the x-axis is a z-axis, the lower limit height of the second cell is 0, the upper limit height of the second cell is z2, the lower limit height of the coverage area of the first cell is z1, and the upper limit height of the coverage area of the first cell is z3, it can be found that the upper limit height z3 of the coverage area of the first cell is greater than the upper limit height z2 of the coverage area of the second cell, and if the flight mode of the drone terminal 331 is the ascent mode, the target cell may be the first cell.

2) If the unmanned aerial vehicle terminal is in a horizontal flight mode, the unmanned aerial vehicle terminal can determine a cell, in the at least one candidate cell, with the average value of the upper limit height and the lower limit height closest to the flight height of the unmanned aerial vehicle terminal as the target cell; and/or if the unmanned aerial vehicle terminal is in a horizontal flight mode, the unmanned aerial vehicle terminal can determine a cell covered by a network device, of at least one network device to which the at least one candidate cell belongs, with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell.

Fig. 4 is a schematic block diagram of a coverage area of a first candidate cell, a coverage area of a second candidate cell, and a position relationship of an unmanned aerial vehicle terminal according to an embodiment of the present application.

Referring to fig. 4, the at least one candidate cell includes a first cell covered by a first network device 310 and a second cell covered by a second network device 320, where if the lower limit height of the coverage area of the second cell is an x-axis, and the vertical direction perpendicular to the x-axis is a z-axis, the lower limit height of the second cell is 0, the upper limit height of the second cell is z2, the lower limit height of the coverage area of the first cell is z1, and the upper limit height of the coverage area of the first cell is z3, it can be found that the height at which the first network device 310 is located is closest to the flight height of the drone terminal 332, and if the flight mode of the drone terminal 332 is a horizontal flight mode, the target cell may be the first cell.

3) If the unmanned aerial vehicle terminal is in a landing mode, the unmanned aerial vehicle terminal can determine a cell with the minimum lower limit height in the at least one candidate cell as the target cell; and/or if the drone terminal is in a landing mode, the drone terminal may determine, as the target cell, a cell covered by a network device with the smallest height among at least one network device to which the at least one candidate cell belongs.

Fig. 5 is a schematic block diagram of a coverage area of a first candidate cell, a coverage area of a second candidate cell, and a position relationship of an unmanned aerial vehicle terminal according to an embodiment of the present application.

Referring to fig. 5, the at least one candidate cell includes a first cell covered by the first network device 310 and a second cell covered by the second network device 320, where if the lower limit height of the coverage area of the second cell is an x-axis, and the vertical direction perpendicular to the x-axis is a z-axis, the lower limit height of the second cell is 0, the upper limit height of the second cell is z2, the lower limit height of the coverage area of the first cell is z1, and the upper limit height of the coverage area of the first cell is z3, it can be found that the upper limit height z3 of the coverage area of the first cell is greater than the upper limit height z2 of the coverage area of the second cell, and if the flight mode of the drone terminal 332 is a landing mode, the target cell may be the second cell.

Taking the example that the at least one candidate cell includes at least one high priority frequency point cell, when at least one neighboring cell satisfies the reselection criterion (for example, the RSRQ measurement value of the neighboring cell is greater than Thresh)_X,HighQThe threshold value or the RSRP measured value of the adjacent cell is more than Thresh_X,HighPA threshold value), if the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can preferentially reselect a cell with the maximum upper limit height or a cell covered by the network equipment with the maximum height; if the unmanned aerial vehicle terminal is in a horizontal flight mode, the unmanned aerial vehicle terminal can be preferentially reselected to a cell covered by network equipment with the height closest to the current flight height of the unmanned aerial vehicle terminal, or the unmanned aerial vehicle terminal can be preferentially reselected to a cell with the average value of the upper limit height and the lower limit height closest to the current flight height of the unmanned aerial vehicle terminal; if the unmanned aerial vehicle terminal is in a landing mode, the unmanned aerial vehicle terminal can preferentially reselect a cell with the minimum lower limit height or a cell covered by the network equipment with the minimum height.

Taking the example that the at least one candidate cell includes at least one low priority frequency point cell, when at least one neighboring cell satisfies the reselection criterion (e.g., RSRQ of the serving cell is less than Thresh)_Serving,LowQAnd the RSRQ measurement value of the adjacent cell is greater than Thresh_X,HighQWhen the threshold value is reached, or the RSRP of the serving cell is smaller than Thresh_Serving,LowPAnd the RSRP measurement value of the adjacent cell is more than Thresh_X,HighPWhen the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can preferentially reselect a cell with the maximum upper limit height or a cell covered by the network equipment with the maximum height; if the unmanned aerial vehicle terminal is in the horizontal flight mode, the unmanned aerial vehicle terminal does not haveThe method comprises the following steps that a human-computer terminal can be preferentially reselected to a cell covered by network equipment with the height closest to the current flight height of an unmanned aerial vehicle terminal, or the unmanned aerial vehicle terminal can be preferentially reselected to a cell with the average value of the upper limit height and the lower limit height closest to the current flight height of the unmanned aerial vehicle terminal; if the unmanned aerial vehicle terminal is in a landing mode, the unmanned aerial vehicle terminal can preferentially reselect a cell with the minimum lower limit height or a cell covered by the network equipment with the minimum height.

Based on the technical scheme, for the unmanned aerial vehicle terminal in the takeoff mode or the landing mode, the unmanned aerial vehicle terminal can preferentially select the cell with the largest residual coverage height to stay in the reselected cell as long as possible on the premise that the RSRP/RSRQ meets the requirement, so that the times of cell reselection are reduced, and further, the influence on connection establishment is reduced. The time for reselecting the cell to serve the unmanned aerial vehicle can be increased to the maximum extent and the times of cell reselection and the probability of connection failure can be reduced for the cell with the height of the cell base station closest to the height of the unmanned aerial vehicle in the horizontal flight mode.

In further embodiments of the present application, the drone terminal may determine, in the at least one candidate cell, a target cell based on altitude information of the at least one candidate cell and a flight mode of the drone terminal, using preconfigured assistance parameters. For example, the drone terminal may determine the target cell using the assistance parameters when the at least one candidate cell includes at least one low priority pilot frequency cell and/or at least one high priority pilot frequency cell that meet cell selection criteria. Wherein the drone terminal may acquire the auxiliary parameter through system information including the auxiliary parameter, for example, the system information including the auxiliary parameter may be a SIB 3. The auxiliary parameter may be information obtained before the cell reselection process, or may also be information obtained in the cell reselection process, which is not specifically limited in this application.

For example, the assistance parameters may include a strongest signal threshold that the drone terminal may receive.

Wherein a difference between the strongest signal quality of the at least one candidate cell and the signal quality of each of the at least one candidate cell is less than the strongest signal threshold. For example, the strongest signal threshold may be the rangeToBestCell referred to above.

In some embodiments of the present application, the altitude information further includes a first altitude threshold, a difference between the maximum upper limit altitude of the at least one candidate cell and the upper limit altitude of each of the at least one candidate cell is smaller than the first altitude threshold, and/or a difference between the maximum located altitude of the at least one network device to which the at least one candidate cell belongs and the located altitude of each of the at least one network device is smaller than the first altitude threshold.

In other words, each candidate cell of the at least one candidate cell is capable of satisfying the coverage requirement of the drone terminal in takeoff mode.

At this time, the drone terminal may determine the target cell in the following manner:

if the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can determine a cell with the best signal quality in the at least one candidate cell as the target cell; and/or if the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can determine the cell with the largest number of beams with the beam quality greater than or equal to a preset threshold value as the target cell; and/or if the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can determine a cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or if the unmanned aerial vehicle terminal is in a takeoff mode, the unmanned aerial vehicle terminal can determine a cell covered by the network equipment with the largest height in the at least one network equipment as the target cell.

For example, if the drone terminal is in a takeoff mode, a parameter first height threshold (ranging height cell) may be used for screening in a plurality of neighboring cells that satisfy the S criterion, and specifically, the following embodiments may be included:

1) screening was performed using only the parameter rangeToHighestCell.

For example, a cell having a difference between the maximum upper height and the upper height of a plurality of cells satisfying the cell selection criterion, which is less than or equal to the ranging tohighestcell, is taken as the at least one candidate cell. At this time, the target cell may be a cell of the at least one candidate cell that satisfies the following condition:

1. a cell with the best signal quality in the at least one candidate cell; and/or the presence of a gas in the gas,

2. a cell with the highest coverage among the at least one candidate cell.

2) Combined screening was performed using the parameters rangeToHighestCell and rangeToBestCell.

For example, a cell in which a difference between a maximum upper-limit height of a plurality of cells satisfying a cell selection criterion and the upper-limit height is less than or equal to a range ToHighestcell and a difference between a maximum measured value of signal quality and a measured value of signal quality of each of the plurality of cells is less than or equal to a range ToBestcell is determined as the at least one candidate cell. At this time, the target cell may be a cell of the at least one candidate cell that satisfies the following condition:

1. and the cell with the largest quantity of beams with the measuring result larger than the preset threshold value.

If there are a plurality of cells with the largest number of beams whose measurement results are greater than a preset threshold, the target cell may be a cell that further satisfies the following conditions among the at least one candidate cell:

a. the cell with the best signal quality; and/or the presence of a gas in the gas,

b. the cell with the largest height of the upper limit.

2. The cell with the best signal quality.

If there are multiple cells with the best signal quality, the target cell may be a cell of the at least one candidate cell that further satisfies the following condition:

a. the cell with the largest quantity of beams with the measuring result larger than a preset threshold value; and/or the presence of a gas in the gas,

b. the cell with the largest height of the upper limit.

3. The cell with the largest height of the upper limit.

If there are more than one cell with the largest upper bound height, the target cell may be a cell of the at least one candidate cell that further satisfies the following condition:

b. and the cell with the largest quantity of beams with the measuring result larger than the preset threshold value.

In some embodiments of the present application, the altitude information further includes a second altitude threshold, a difference between an average of an upper limit altitude and a lower limit altitude of each candidate cell in the at least one candidate cell and the flight altitude of the drone terminal is smaller than the second altitude threshold, and/or a difference between an altitude of each network device in the at least one network device to which the at least one candidate cell belongs and the flight altitude of the drone terminal is smaller than the second altitude threshold.

In other words, each candidate cell of the at least one candidate cell is capable of satisfying the coverage requirements of the drone terminal in horizontal flight mode.

if the unmanned aerial vehicle terminal is in a horizontal flight mode, the unmanned aerial vehicle terminal can determine a cell with the best signal quality in the at least one candidate cell as the target cell; and/or if the drone terminal is in a horizontal flight mode, the drone terminal may determine a cell including a cell having a maximum number of beams with a beam quality greater than or equal to a preset threshold as the target cell; and/or if the unmanned aerial vehicle terminal is in a horizontal flight mode, the unmanned aerial vehicle terminal can determine a cell, of which the average value of the upper limit altitude and the lower limit altitude in the at least one candidate cell is closest to the flight altitude of the unmanned aerial vehicle terminal, as the target cell; and/or if the unmanned aerial vehicle terminal is in a horizontal flight mode, the unmanned aerial vehicle terminal can determine a cell covered by a network device, of at least one network device to which the at least one candidate cell belongs, with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell.

For example, if the drone terminal is in a horizontal flight mode, a second height threshold (ranging _ current _ high _ cell) may be used for screening among a plurality of neighboring cells satisfying the S criterion, and there are several following embodiments:

1) screening was performed using only the parameter rangetocurrentlightcell.

For example, a cell in which the difference between the altitude at which each of at least one network device to which a plurality of cells satisfying the cell selection criterion belong and the current flying altitude of the drone terminal is less than or equal to the rangeToCurrentHightCell is taken as the at least one candidate cell. At this time, the target cell may be a cell of the at least one candidate cell that satisfies the following condition:

2. the at least one network device to which the at least one candidate cell belongs is located at a cell covered by a network device having an altitude closest to the current flying altitude of the drone.

2) Combined screening was performed using the parameters rangetocurrentlightcell and rangeToBestCell.

For example, a cell, in which the difference between the altitude at which each of at least one network device to which a plurality of cells that satisfy the cell selection criterion belong and the current flying altitude of the drone terminal is less than or equal to that of the rangetocurrenthithcell, and the difference between the maximum measured value of the signal quality in the plurality of cells and the measured value of the signal quality in each of the plurality of cells is less than or equal to that of the rangeToBestCell, is taken as the at least one candidate cell. At this time, the target cell may be a cell of the at least one candidate cell that satisfies the following condition:

b. the altitude is closest to the cell covered by the network device of the current flying altitude of the unmanned aerial vehicle terminal.

2. The cell with the best signal quality.

3. The altitude is closest to the cell covered by the network device of the current flying altitude of the unmanned aerial vehicle terminal.

If there are a plurality of cells covered by the network device at the altitude closest to the current altitude of flight of the drone terminal, the target cell may be a cell of the at least one candidate cell that further satisfies the following condition:

In some embodiments of the present application, the altitude information further includes a third altitude threshold, a difference between a lower altitude of each of the at least one candidate cells and a minimum lower altitude of the at least one candidate cell is smaller than the third altitude threshold, and/or a difference between an altitude of each of at least one network device to which the at least one candidate cell belongs and a minimum altitude of the at least one network device is smaller than the third altitude threshold.

In other words, each candidate cell of the at least one candidate cell is capable of satisfying the coverage requirement of the drone terminal in the landing mode.

if the unmanned aerial vehicle terminal is in a landing mode, the unmanned aerial vehicle terminal can determine a cell with the best signal quality in the at least one candidate cell as the target cell; and/or if the drone terminal is in a landing mode, the drone terminal may determine a cell including a cell having a beam quality greater than or equal to a preset threshold and the largest number of beams as the target cell; and/or if the unmanned aerial vehicle terminal is in a landing mode, the unmanned aerial vehicle terminal can determine a cell with the minimum upper limit height in the at least one candidate cell as the target cell; and/or if the drone terminal is in a landing mode, the drone terminal may determine a cell covered by a network device with the smallest height in the at least one network device as the target cell.

For example, if the drone terminal is in the landing mode, a third height threshold (ranging to lowestcell) may be used for screening in a plurality of neighboring cells satisfying the S criterion, and there are several following embodiments:

1) and screening was performed using only the parameter rangeToLowestCell.

For example, a cell in which a difference between each lower-limit height of a plurality of cells satisfying the cell selection criterion and a minimum lower-limit height of the plurality of cells is less than or equal to the ranging tohighestcell is taken as the at least one candidate cell. At this time, the target cell may be a cell of the at least one candidate cell that satisfies the following condition:

1. the cell with the best signal quality; and/or the presence of a gas in the gas,

2. the lower limit height is the smallest cell.

2) Combined screening was performed using the parameters rangeToLowestCell and rangeToBestCell.

For example, a cell in which a difference between each lower-limit height of a plurality of cells satisfying a cell selection criterion and a minimum lower-limit height of the plurality of cells is less than or equal to a range ToHighestcell and a difference between a maximum measurement value of signal quality in the plurality of cells and a measurement value of signal quality of each of the plurality of cells is less than or equal to a range ToBestcell is determined as the at least one candidate cell.

At this time, the target cell may be a cell of the at least one candidate cell that satisfies the following condition:

b. the lower limit height is the smallest cell.

2. The cell with the best signal quality.

b. the lower limit height is the smallest cell.

3. The lower limit height is the smallest cell.

If there are a plurality of cells with the minimum lower height, the target cell may be a cell of the at least one candidate cell that further satisfies the following condition:

Based on the technical scheme, aiming at the reselection of cells with different frequencies and different frequencies of the same priority, based on different flight modes, the height dimension of the target cell is screened by introducing the range value or tolerance of the target coverage height (such as the highest height in a takeoff mode, the current flight height in a horizontal flight mode and the lowest height in a landing mode), so that certain signal quality is ensured, the cells with the beam number of which the measurement result is greater than a preset threshold value can meet the requirements of the unmanned aerial vehicle on coverage in different flight modes, the unmanned aerial vehicle can stay in the reselected cell as long as possible, the reselection frequency of the cell is reduced, and the probability of connection failure is reduced.

In some embodiments of the present application, the drone terminal may acquire the altitude information through system information. For example, the unmanned aerial vehicle terminal obtains system information sent by a network device, where the system information includes the altitude information. For example, the system information may be SIB3 or other SIBs.

The preferred embodiments of the present application have been described in detail with reference to the accompanying drawings, however, the present application is not limited to the details of the above embodiments, and various simple modifications can be made to the technical solution of the present application within the technical idea of the present application, and these simple modifications are all within the protection scope of the present application.

For example, the various features described in the foregoing detailed description may be combined in any suitable manner without contradiction, and various combinations that may be possible are not described in this application in order to avoid unnecessary repetition.

For example, various embodiments of the present application may be arbitrarily combined with each other, and the same should be considered as the disclosure of the present application as long as the concept of the present application is not violated.

It should be understood that, in the various method embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Method embodiments of the present application are described in detail above in conjunction with fig. 2-5, and apparatus embodiments of the present application are described in detail below in conjunction with fig. 6-8.

Fig. 6 is a schematic block diagram of a drone terminal 400 according to an embodiment of the present application.

As shown in fig. 6, the drone terminal 400 may include:

a communication unit 410 for obtaining altitude information for at least one candidate cell;

a processing unit 420, configured to determine a target cell from the at least one candidate cell according to the altitude information and a flight mode of the drone terminal;

the communication unit 410 is further configured to perform cell reselection based on the target cell.

an upper bound height for coverage of each of the at least one candidate cell;

a lower bound height covered by each of the at least one candidate cell; and

In some embodiments of the present application, each of the at least one candidate cell satisfies a cell selection criterion.

In some embodiments of the present application, the at least one candidate cell is a cell of neighbor cells and/or serving cells of the drone terminal that satisfies the cell selection criterion.

In some embodiments of the present application, the at least one candidate cell comprises:

at least one pilot frequency cell with the frequency point priority lower than that of the service cell; and/or

And the frequency point priority is higher than that of the serving cell.

In some embodiments of the present application, the processing unit 420 is specifically configured to:

if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell covered by the network equipment with the largest height in at least one network equipment to which the at least one candidate cell belongs as the target cell.

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell, in the at least one candidate cell, with the average value of the upper limit altitude and the lower limit altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell covered by a network device with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal in at least one network device to which the at least one candidate cell belongs as the target cell.

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the minimum lower limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a landing mode, determining a cell covered by the network equipment with the minimum height in at least one network equipment to which the at least one candidate cell belongs as the target cell.

at least one pilot frequency cell with the frequency point priority equal to that of the service cell; and/or

The frequency point is equal to the frequency point of the service cell.

In some embodiments of the present application, the difference between the strongest signal quality of the at least one candidate cell and the signal quality of each of the at least one candidate cell is less than the strongest signal threshold.

if the unmanned aerial vehicle terminal is in a takeoff mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a takeoff mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell covered by the network equipment with the largest height in the at least one network equipment as the target cell.

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

In some embodiments of the present application, the altitude information further includes a third altitude threshold, a difference between the lower altitude of each of the at least one candidate cells and the minimum lower altitude of the at least one candidate cell is smaller than the third altitude threshold, and/or a difference between the altitude of each of at least one network device to which the at least one candidate cell belongs and the minimum altitude of the at least one network device is smaller than the third altitude threshold.

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the minimum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a landing mode, determining a cell covered by the network equipment with the minimum height in the at least one network equipment as the target cell.

In some embodiments of the present application, the communication unit 410 is specifically configured to:

acquiring the altitude information for the at least one candidate cell by acquiring system information including the altitude information for the at least one candidate cell.

It is to be understood that apparatus embodiments and method embodiments may correspond to one another and that similar descriptions may refer to method embodiments. Specifically, the unmanned aerial vehicle terminal 400 shown in fig. 6 may correspond to a corresponding main body in executing the method 200 in the embodiment of the present application, and the foregoing and other operations and/or functions of each unit in the unmanned aerial vehicle terminal 400 are respectively for implementing a corresponding flow in the method shown in fig. 2, and are not repeated herein for brevity.

The communication device of the embodiment of the present application is described above in connection with fig. 6 from the perspective of functional modules. It should be understood that the functional modules may be implemented by hardware, by instructions in software, or by a combination of hardware and software modules.

Specifically, the steps of the method embodiments in the present application may be implemented by integrated logic circuits of hardware in a processor and/or instructions in the form of software, and the steps of the method disclosed in conjunction with the embodiments in the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor.

Alternatively, the software modules may be located in random access memory, flash memory, read only memory, programmable read only memory, electrically erasable programmable memory, registers, and the like, as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps in the above method embodiments in combination with hardware thereof.

For example, the communication unit and the processing unit may be implemented by a transceiver and a processor, respectively.

Fig. 7 is a schematic structural diagram of a communication device 500 according to an embodiment of the present application.

As shown in fig. 7, the communication device 500 includes a processor 510, and the processor 510 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

With continued reference to fig. 7, the communication device 500 may also include a memory 520. The memory 520 may be used to store instructions and codes, instructions, etc. that may be executed by the processor 510. From the memory 520, the processor 510 can call and run a computer program to implement the method in the embodiment of the present application.

The memory 520 may be a separate device from the processor 510, or may be integrated into the processor 510.

With continued reference to fig. 7, the communication device 500 may further include a transceiver 530, and the processor 510 may control the transceiver 530 to communicate with other devices, and specifically, may transmit information or data to the other devices or receive information or data transmitted by the other devices.

The transceiver 530 may include a transmitter and a receiver, among others. The transceiver 530 may further include one or more antennas.

It should be understood that the communication device 500 may be a terminal device in this embodiment, and the communication device 500 may implement a corresponding process implemented by the terminal device in each method in this embodiment, that is, the communication device 500 in this embodiment may correspond to the unmanned aerial vehicle terminal 400 in this embodiment, and may correspond to a corresponding main body in executing the method 200 in this embodiment, which is not described herein again for brevity. Similarly, the communication device 500 may be a network device according to an embodiment of the present application, and the communication device 500 may cooperate with the drone terminal 400 to form the communication system shown in fig. 1, which is not described herein again for brevity.

It should be understood that the various components in the communication device 500 are connected by a bus system that includes a power bus, a control bus, and a status signal bus in addition to a data bus.

In addition, an embodiment of the present application further provides a chip, which may be an integrated circuit chip, and has signal processing capability, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiment of the present application.

Alternatively, the chip may be applied to various communication devices, so that the communication device mounted with the chip can execute the methods, steps and logic blocks disclosed in the embodiments of the present application.

Fig. 8 is a schematic structural diagram of a chip according to an embodiment of the present application.

Referring to fig. 8, the chip 600 includes a processor 610.

From which processor 610 may invoke and execute a computer program to implement the methods of the embodiments of the present application.

With continued reference to fig. 8, the chip 600 may further include a memory 620.

From the memory 620, the processor 610 may call and run a computer program to implement the method in the embodiment of the present application. The memory 620 may be used to store instructions and codes, instructions, etc. that may be executed by the processor 610. The memory 620 may be a separate device from the processor 610 or may be integrated into the processor 610.

With continued reference to fig. 8, the chip 600 may further include an input interface 630.

The processor 610 may control the input interface 630 to communicate with other devices or chips, and in particular, may obtain information or data transmitted by other devices or chips.

With continued reference to fig. 8, the chip 600 may further include an output interface 640.

The processor 610 may control the output interface 640 to communicate with other devices or chips, and in particular, may output information or data to the other devices or chips.

It should be understood that the chip 600 may be applied to a network device in this embodiment, and the chip may implement a corresponding process implemented by the network device in each method in this embodiment, and may also implement a corresponding process implemented by a terminal device in each method in this embodiment, which is not described herein again for brevity.

It should also be understood that the chips mentioned in the embodiments of the present application may also be referred to as a system-on-chip, a system-on-chip or a system-on-chip, etc. It will also be appreciated that the various components in the chip 600 are connected by a bus system that includes a power bus, a control bus, and a status signal bus in addition to a data bus.

The processor may include, but is not limited to:

general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, and the like.

The processor may be configured to implement or perform the methods, steps, and logic blocks disclosed in the embodiments of the present application. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, eprom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

The memory includes, but is not limited to:

volatile memory and/or non-volatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of example, but not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic random access memory (DDR SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DR RAM).

It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

The embodiment of the application also provides a computer readable storage medium for storing the computer program. The computer readable storage medium stores one or more programs, the one or more programs comprising instructions, which when executed by a portable electronic device comprising a plurality of applications, enable the portable electronic device to perform the methods of the illustrated embodiments of methods 300-500.

Optionally, the computer-readable storage medium may be applied to the network device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the network device in each method in the embodiment of the present application, which is not described herein again for brevity.

Optionally, the computer-readable storage medium may be applied to the mobile terminal/terminal device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the mobile terminal/terminal device in each method in the embodiment of the present application, which is not described herein again for brevity.

The embodiment of the application also provides a computer program product comprising the computer program.

Optionally, the computer program product may be applied to the network device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the network device in each method in the embodiment of the present application, which is not described herein again for brevity.

Optionally, the computer program product may be applied to the mobile terminal/terminal device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the mobile terminal/terminal device in each method in the embodiment of the present application, which is not described herein again for brevity.

The embodiment of the application also provides a computer program. The computer program, when executed by a computer, enables the computer to perform the methods of the illustrated embodiments of methods 300-500.

Optionally, the computer program may be applied to the network device in the embodiment of the present application, and when the computer program runs on a computer, the computer is enabled to execute the corresponding process implemented by the network device in each method in the embodiment of the present application, and for brevity, details are not described here again.

An embodiment of the present application further provides a communication system, where the communication system may include the unmanned aerial vehicle terminal 400 shown in fig. 6 and a network device communicable with the unmanned aerial vehicle terminal 400 to form a communication system, such as the communication system 100 in fig. 1, and details are not repeated here for brevity.

It should be noted that the term "system" and the like herein may also be referred to as "network management architecture" or "network system" and the like.

It is also to be understood that the terminology used in the embodiments of the present application and the appended claims is for the purpose of describing particular embodiments only, and is not intended to be limiting of the embodiments of the present application.

For example, as used in the examples of this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those of skill in the art would appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the embodiments of the present application.

If implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially implemented or make a contribution to the prior art, or may be implemented in the form of a software product stored in a storage medium and including several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: u disk, removable hard disk, read only memory, random access memory, magnetic or optical disk, etc. for storing program codes.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other ways.

For example, the division of a unit or a module or a component in the above-described device embodiments is only one logical function division, and there may be other divisions in actual implementation, for example, a plurality of units or modules or components may be combined or may be integrated into another system, or some units or modules or components may be omitted, or not executed.

Also for example, the units/modules/components described above as separate/display components may or may not be physically separate, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the units/modules/components can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

Finally, it should be noted that the above shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The above description is only a specific implementation of the embodiments of the present application, but the scope of the embodiments of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the embodiments of the present application, and all the changes or substitutions should be covered by the scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims

A method for reselecting a cell, comprising:

obtaining altitude information for at least one candidate cell;

determining a target cell from the at least one candidate cell according to the altitude information and the flight mode of the unmanned aerial vehicle terminal;

and performing cell reselection based on the target cell.
The method according to claim 1, wherein the at least one candidate cell comprises a serving cell of the drone terminal and/or at least one neighbor cell of the serving cell.
The method according to claim 1 or 2, wherein the height information comprises at least one of the following information:

an upper bound height for coverage of each of the at least one candidate cell;

a lower bound height covered by each of the at least one candidate cell; and

an altitude at which the network device to which the at least one candidate cell belongs is located.
The method according to any of claims 1 to 3, wherein each of the at least one candidate cells satisfies a cell selection criterion.
The method according to any of claims 1 to 4, wherein the at least one candidate cell is a cell of neighbor cells and/or serving cells of the drone terminal that satisfies the cell selection criterion.
The method according to claim 4 or 5, wherein the at least one candidate cell comprises:

at least one pilot frequency cell with the frequency point priority lower than that of the service cell; and/or the presence of a gas in the gas,

and the frequency point priority is higher than that of the serving cell.
The method of claim 6, wherein determining a target cell from the at least one candidate cell according to the altitude information and a flight mode of the drone terminal comprises:

if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell covered by the network equipment with the largest height in at least one network equipment to which the at least one candidate cell belongs as the target cell.
The method of claim 6, wherein determining a target cell from the at least one candidate cell according to the altitude information and a flight mode of the drone terminal comprises:

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell, in the at least one candidate cell, with the average value of the upper limit altitude and the lower limit altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell covered by a network device with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal in at least one network device to which the at least one candidate cell belongs as the target cell.
The method of claim 6, wherein determining a target cell from the at least one candidate cell according to the altitude information and a flight mode of the drone terminal comprises:

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the minimum lower limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a landing mode, determining a cell covered by the network equipment with the minimum height in at least one network equipment to which the at least one candidate cell belongs as the target cell.
The method according to claim 4 or 5, wherein the at least one candidate cell comprises:

at least one pilot frequency cell with the frequency point priority equal to that of the service cell; and/or the presence of a gas in the gas,

the frequency point is equal to the frequency point of the service cell.
The method of claim 10, wherein the difference between the strongest signal quality of the at least one candidate cell and the signal quality of each of the at least one candidate cell is less than a preconfigured strongest signal threshold.
The method according to claim 10 or 11, wherein the altitude information further includes a first altitude threshold, and a difference between a maximum upper altitude of the at least one candidate cell and an upper altitude of each of the at least one candidate cell is smaller than the first altitude threshold, and/or a difference between a maximum located altitude of at least one network device to which the at least one candidate cell belongs and a located altitude of each of the at least one network device is smaller than the first altitude threshold.
The method of claim 12, wherein determining a target cell from the at least one candidate cell according to the altitude information and a flight pattern of the drone terminal comprises:

if the unmanned aerial vehicle terminal is in a takeoff mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a takeoff mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell covered by the network equipment with the largest height in the at least one network equipment as the target cell.
The method according to claim 10 or 11, wherein the altitude information further comprises a second altitude threshold, and the difference between the average of the upper and lower altitude of each of the at least one candidate cell and the altitude of the drone terminal is smaller than the second altitude threshold, and/or the difference between the altitude of each of the at least one network device to which the at least one candidate cell belongs and the altitude of the drone terminal is smaller than the second altitude threshold.
The method of claim 14, wherein determining a target cell from the at least one candidate cell according to the altitude information and a flight pattern of the drone terminal comprises:

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell, in the at least one candidate cell, with the average value of the upper limit altitude and the lower limit altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell covered by a network device with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal in at least one network device to which the at least one candidate cell belongs as the target cell.
The method according to claim 10 or 11, wherein the altitude information further comprises a third altitude threshold, and the difference between the lower altitude of each of the at least one candidate cells and the minimum lower altitude of the at least one candidate cell is smaller than the third altitude threshold, and/or the difference between the altitude of each of at least one network device to which the at least one candidate cell belongs and the minimum altitude of the at least one network device is smaller than the third altitude threshold.
The method of claim 16, wherein determining a target cell from the at least one candidate cell according to the altitude information and a flight pattern of the drone terminal comprises:

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the minimum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a landing mode, determining a cell covered by the network equipment with the minimum height in the at least one network equipment as the target cell.
The method according to any of claims 1 to 17, wherein said obtaining altitude information for at least one candidate cell comprises:

acquiring the altitude information for the at least one candidate cell by acquiring system information including the altitude information for the at least one candidate cell.
An unmanned aerial vehicle terminal, comprising:

a communication unit for acquiring altitude information for at least one candidate cell;

a processing unit, configured to determine a target cell from the at least one candidate cell according to the altitude information and a flight mode of the drone terminal;

the communication unit is further configured to perform cell reselection based on the target cell.
The drone terminal of claim 19, wherein the at least one candidate cell comprises a serving cell of the drone terminal and/or at least one neighbor cell of the serving cell.
The drone terminal of claim 19 or 20, wherein the altitude information includes at least one of:

an upper bound height for coverage of each of the at least one candidate cell;

a lower bound height covered by each of the at least one candidate cell; and

an altitude at which the network device to which the at least one candidate cell belongs is located.
The drone terminal of any one of claims 19 to 21, wherein each of the at least one candidate cells satisfies cell selection criteria.
The drone terminal of any one of claims 19 to 22, wherein each of the at least one candidate cells satisfies cell selection criteria.
The drone terminal of claim 22 or 23, wherein the at least one candidate cell comprises:

at least one pilot frequency cell with the frequency point priority lower than that of the service cell; and/or the presence of a gas in the gas,

and the frequency point priority is higher than that of the serving cell.
The unmanned aerial vehicle terminal of claim 24, wherein the processing unit is specifically configured to:

if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell covered by the network equipment with the largest height in at least one network equipment to which the at least one candidate cell belongs as the target cell.
The unmanned aerial vehicle terminal of claim 24, wherein the processing unit is specifically configured to:

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell, in the at least one candidate cell, with the average value of the upper limit altitude and the lower limit altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell covered by a network device with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal in at least one network device to which the at least one candidate cell belongs as the target cell.
The unmanned aerial vehicle terminal of claim 24, wherein the processing unit is specifically configured to:

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the minimum lower limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a landing mode, determining a cell covered by the network equipment with the minimum height in at least one network equipment to which the at least one candidate cell belongs as the target cell.
The drone terminal of claim 22 or 23, wherein the at least one candidate cell comprises:

at least one pilot frequency cell with the frequency point priority equal to that of the service cell; and/or the presence of a gas in the gas,

the frequency point is equal to the frequency point of the service cell.
The drone terminal of claim 28, wherein a difference between a strongest signal quality of the at least one candidate cell and a signal quality of each of the at least one candidate cell is less than the strongest signal threshold.
The drone terminal of claim 28 or 29, wherein the altitude information further comprises a first altitude threshold, and a difference between a maximum upper altitude of the at least one candidate cell and an upper altitude of each of the at least one candidate cell is smaller than the first altitude threshold, and/or a difference between a maximum located altitude of at least one network device to which the at least one candidate cell belongs and a located altitude of each of the at least one network device is smaller than the first altitude threshold.
The unmanned aerial vehicle terminal of claim 30, wherein the processing unit is specifically configured to:

if the unmanned aerial vehicle terminal is in a takeoff mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a takeoff mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell with the maximum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a take-off mode, determining a cell covered by the network equipment with the largest height in the at least one network equipment as the target cell.
The drone terminal of claim 28 or 29, wherein the altitude information further comprises a second altitude threshold, and wherein a difference between an average of an upper altitude and a lower altitude of each of the at least one candidate cell and the altitude of the drone terminal is less than the second altitude threshold, and/or a difference between the altitude at which each of the at least one network device to which the at least one candidate cell belongs and the altitude of the drone terminal is less than the second altitude threshold.
The unmanned aerial vehicle terminal of claim 32, wherein the processing unit is specifically configured to:

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell, in the at least one candidate cell, with the average value of the upper limit altitude and the lower limit altitude closest to the flight altitude of the unmanned aerial vehicle terminal as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a horizontal flight mode, determining a cell covered by a network device with the altitude closest to the flight altitude of the unmanned aerial vehicle terminal in at least one network device to which the at least one candidate cell belongs as the target cell.
The drone terminal of claim 28 or 29, wherein the altitude information further comprises a third altitude threshold, a difference between a lower altitude of each of the at least one candidate cells and a minimum lower altitude of the at least one candidate cell being less than the third altitude threshold, and/or a difference between an altitude at which each of at least one network device of the at least one candidate cell belongs and a minimum altitude of the at least one network device being less than the third altitude threshold.
The unmanned aerial vehicle terminal of claim 34, wherein the processing unit is specifically configured to:

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the best signal quality in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the largest number of beams with the beam quality larger than or equal to a preset threshold value as the target cell; and/or the presence of a gas in the gas,

if the unmanned aerial vehicle terminal is in a landing mode, determining a cell with the minimum upper limit height in the at least one candidate cell as the target cell; and/or the presence of a gas in the gas,

and if the unmanned aerial vehicle terminal is in a landing mode, determining a cell covered by the network equipment with the minimum height in the at least one network equipment as the target cell.
The drone terminal of any one of claims 19 to 35, wherein the communication unit is specifically configured to:

acquiring the altitude information for the at least one candidate cell by acquiring system information including the altitude information for the at least one candidate cell.
An unmanned aerial vehicle terminal, comprising:

a processor, a memory for storing a computer program, and a transceiver, the processor for invoking and executing the computer program stored in the memory to perform the method of any one of claims 1 to 18.
A chip, comprising:

a processor for calling and running a computer program from a memory so that a device on which the chip is installed performs the method of any one of claims 1 to 18.
A computer-readable storage medium for storing a computer program which causes a computer to perform the method of any one of claims 1 to 18.
A computer program product comprising computer program instructions to cause a computer to perform the method of any one of claims 1 to 18.
A computer program, characterized in that the computer program causes a computer to perform the method according to any one of claims 1 to 18.